Rocket Lab recovers booster again after launch with BlackSky satellites

An Electron rocket lifts off Friday with two BlackSky Earth-imaging satellites. Credit: Rocket Lab

Two BlackSky optical Earth-imaging satellites rode an Electron launcher into orbit Friday from New Zealand, while the Electron’s first stage booster gently parachuted into the Pacific Ocean as engineers consider abandoning airborne rocket recovery in favor of ship-based retrieval and reuse.

Rocket Lab engineers will inspect and test components on the Electron booster stage once it returns to the company’s factory in Auckland to see how well the hardware weathered the rocket’s scorching-hot re-entry back through the atmosphere, and more crucially, how the booster withstood the corrosive effects of salt water after splashdown.

The 59-foot-tall (18-meter) carbon-fiber rocket took off from Rocket Lab’s privately-owned spaceport on the North Island of New Zealand at 5:14:56 a.m. EDT (0914:56 UTC; 10:14:56 p.m. local time).

Nine kerosene-fueled Rutherford main engines on the first stage fired two-and-a-half minutes before switching off, allowing the booster to drop away from the Electron’s second stage, which fired a single engine to continue the climb into orbit with two commercial optical remote sensing microsatellites for the U.S. company BlackSky.

The booster arced downrange and briefly climbed above the internationally-recognized boundary of space, then plunged back into the atmosphere over the Pacific Ocean.

The company has attempted to catch returning first stage boosters on two attempts with helicopters over the Pacific downrange from the New Zealand spaceport. On the first try last May, the helicopter briefly captured the booster’s parachute with a long boom, but the pilot commanded release of the rocket and its parachute after observing unexpected loads on the aircraft.

Rocket Lab called off a second catch attempt with a helicopter in November due to a telemetry loss from the rocket on descent back into the atmosphere.

For Friday’s mission, Rocket Lab did not include the helicopter in the recovery attempt, and instead planned to pull the booster from the ocean after splashdown under parachute. Engineers will bring the booster back to shore for inspections, refurbishment, and testing as Rocket Lab aims to eventually reuse rockets on multiple flights.

The boosters Rocket Lab builds for recovery attempts come with red markings, along with a heat shield and a silver thermal protection coating on the outer airframe of the first stage.

The booster was expected to reach a top speed of 5,150 mph (8,300 kilometers per hour). Aerodynamic drag slowed the rocket’s velocity as external temperatures built up to 4,350 degrees Fahrenheit (2,400 degrees Celsius). Then a drogue chute and main chute deployed to slow the booster’s descent for splashdown. Rocket Lab confirmed the booster reached the Pacific Ocean as intended.

Rocket Lab has recovered six Electron boosters since the first try in November 2020. Four were intentionally recovered from the ocean, and two involved a helicopter catch attempt. The company originally aimed to catch boosters with the helicopter to prevent corrosion on the rocket’s engines and avionics from sea water.

Inspections of the booster from the previous rocket recovery last year showed the Electron first stage was in better shape than expected, despite a dunk in the salt water of the Pacific.

“It turns out Electron survives a swim in the ocean well enough that many of its components actually pass re-qualification for flight, so for this mission we are putting the theory to the test of whether we need a helicopter at all,” said Murielle Baker, a Rocket Lab spokesperson and co-host of the company’s launch webcast Friday. “We have added waterproofing modifications to the stage to protect some of the key bits we want to keep dry, and depending on how well ocean recovery performs this go-around, the results may convince the team to stick with marine recovery altogether.

“The benefit of that would mean not only big savings cost to our recovery and reusability R&D, but it would also open up more flexibility for our launch windows and take us from 50% of Electron missions being suited for recovery up to as high as 70% of our missions,” Baker said.

Michael Daly, a Rocket Lab special projects engineer working on Electron reusability, said his team on the recovery boat will clean sensitive parts of the rocket prevent corrosion. Engineers and technicians on the recovery team will perform “operations like de-salting the engines, trying to remove all that bad salt water, and basically just trying to make the rocket survive that experience with the water.

“We’re going to be doing some modifications to the engines as well, in terms of the design to make them more resilient,” Daly said. “A mixture of these de-salting operations once it comes out of the water, as well as these design changes, will hopefully mean that we have to do minimal testing once we get these guys back.”

Once the booster is back at Rocket Lab’s Auckland factory, the company will disassemble and inspect the nine main engines, and remove avionics for examination and re-testing. Rocket Lab has already hot-fired a Rutherford engine recovered from an Electron flight.

Artist’s illustration of BlackSky satellites in orbit. Credit: BlackSky

The two BlackSky satellites launched Friday were deployed by Rocket Lab’s kick stage into a target orbit 280 miles (450 kilometers) above Earth, at an inclination of 42 degrees to the equator.

The two BlackSky Earth observation spacecraft, each about the size of a small refrigerator, were stacked one on top of the other for launch, fixed to a dual-payload adapter structure. The upper satellite deployed from the kick stage first, followed by separation of the adapter, then the release of the satellite in the lower berth around 57 minutes after liftoff.

Each BlackSky satellite weighs about 121 pounds (55 kilograms). The satellites are built by LeoStella, a joint venture between BlackSky and Thales Alenia Space, a major European satellite manufacturer. LeoStella’s production facility is located in Tukwila, Washington, a suburb of Seattle.

BlackSky, with offices in Seattle and Herndon, Virginia, is deploying a fleet of small remote sensing satellites to provide high-resolution Earth imagery to commercial and government clients.

One big customer for BlackSky is the U.S. military and intelligence agencies. BlackSky has agreements to sell commercial imagery to NASA, the National Reconnaissance Office and the National Geospatial-Intelligence Agency.

BlackSky says the launch Friday expanded the company’s fleet to 16 operational satellites. The spacecraft were the 18th and 19th satellites launched overall for BlackSky’s commercial Earth-imaging constellation.

The optical remote sensing fleet provides high-frequency revisit capability, capturing images of locations around the world in daylight up to 15 times per day. Spaceflight, the Seattle-based launch broker and rideshare launch provider, managed the launch with Rocket Lab on behalf of BlackSky.

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